列车车载分布式监测系统的时间同步方法研究
Research on Time Synchronization Method for Train Distributed System
张冰 1王志良 1曹熙 2田亮1
作者信息
- 1. 中国铁道科学研究院集团有限公司 机车车辆研究所,北京 100081
- 2. 北京纵横机电科技有限公司,北京 100094
- 折叠
摘要
针对车载分布式监测系统内各子节点系统时钟不一致的情况,提出了一种基于软件实现的、不依赖额外时钟同步设备且精度高于NTP协议的系统同步方法.计算各子节点与中心节点的时间偏差,此时间偏差不用于调节子节点的本地时钟,而是与子节点采集的数据及对应时间戳一起发送至中心节点.中心节点可根据时间偏差对各设备上报数据的时间戳进行修正,以此达到分布式系统同步的目的.而在计算子节点与中心节点的时间偏差中,相较于传统的NTP网络时间协议,还需考虑报文在软件应用层到网卡之间的传输时延.为计算此时延,引入比NTP精确度更高的PTP参考主机预先对该时延进行估计,由此得到分布式系统的时偏精度高于传统的NTP协议.
Abstract
Aiming at the inconsistency of the system clock of each sub-node in the vehicle distributed monitoring system,a system synchronization method is proposed based on software which does not rely on additional clock synchronization devices and has higher accuracy than NTP protocol.Firstly,the time deviation between each child node and the central node is calculated,and this time deviation is not used to adjust the local clock of the child node,but is sent to the central node together with the data collected by the child node and the corresponding timestamp.The central node can correct the timestamp of the data reported by each device according to the time bias,so as to achieve the purpose of distributed system synchronization.In calculating the time deviation between the child node and the central node,compared with the traditional NTP network time protocol,the transmission delay of packets between the software application layer and the network card needs to be considered.In order to calculate this delay,a PTP reference host with higher accuracy than NTP is introduced to estimate the delay in advance,and the time offset accuracy of the distributed system is higher than that of the traditional NTP protocol.
关键词
车载/分布式系统/同步/系统时钟偏差/网络时间协议Key words
in train/distributed system/synchronization/system clock deviation/network time protocol引用本文复制引用
出版年
2024
NETL
NSTL
万方数据